Kenya is drawing up a timetable for closing the Dadaab refugee camp, home to about 350,000 Somali refugees, the interior minister announced Wednesday.

Having suffered multiple attacks claimed by the Islamist Somali group al-Shabab, Kenya has set up a taskforce to handle the closure plan, Interior Minister Joseph Nkaissery said.

"They will present the timetable based on all the resources required," he told a news conference, adding that the country had already allocated state funds to proceed with the program. "The government has commenced the exercise of closing the complex of Dadaab refugee camp."

He did not specify whether new action other than the existing voluntary repatriation program had been taken.

Kenya announced Friday that it would close the Dadaab and Kakuma refugee camps "within the shortest time possible," citing security concerns, particularly from al-Shabab, a Somali-backed Islamist group that has carried out several mass attacks in Kenya. It said that hosting the refugees, who are mostly from Somalia, posed "immense security challenges."

U.S. Secretary of State John Kerry released a statement Wednesday expressing deep concern about the decision, urging Kenya "to maintain its longstanding leadership role in protecting and sheltering victims of violence and trauma...and not forcibly repatriate refugees."

The United Nations also released a statement this week saying that it viewed the plans by Kenya's government with "profound concern." It urged the government to "avoid taking any action that might be at odds with its international obligations" and said the safety of hundreds of thousands of refugees hinges on Kenya's generosity.

Kenya's government Friday acknowledged its decision will cause harm to the refugees and said the international community must take steps to minimize their pain and suffering.

The country hosts about 600,000 refugees in all. About three-fourths are from Somalia, with most of the others coming from South Sudan.

Kenya's government has threatened to close the refugee camps in the past, but never followed through.

Al-Shabab has carried out several major attacks on Kenyan territory, most notably the 2013 attack on Nairobi's Westgate Mall that killed 67 people and the 2015 attack on a college in the town of Garissa that killed 148.

Al-Shabab began launching attacks in Kenya after Kenyan troops entered Somalia to fight the militant group in 2011.